The presidential oath of office contains 35 words and one core promise: to “preserve, protect and defend the Constitution of the United States.” Since virtually the moment Donald J. Trump took that oath two years ago, he has been violating it. He has

tried to shake the public’s confidence in one democratic institution after another, including

the press,

federal law enforcement and the

federal judiciary.

The unrelenting chaos that Trump creates can sometimes obscure the big picture. But the big picture is simple: The United States has never had a president as demonstrably unfit for the office as Trump. And it’s becoming clear that 2019 is likely to be dominated by a single question: What are we going to do about it?

The easy answer is to wait — to allow the various investigations of Trump to run their course and ask voters to deliver a verdict in 2020. That answer has one great advantage. It would avoid the national trauma of overturning an election result. Ultimately, however, waiting is too dangerous. The cost of removing a president from office is smaller than the cost of allowing this president to remain.

He has already shown, repeatedly, that

he will hurt the country in order to help himself. He will damage American interests around the world and

defense secretary who defended our alliances with NATO and South Korea is gone. So is

the attorney general who refused to let Trump subvert a federal investigation into himself. The administration is increasingly filled with lackeys and enablers. Trump has become freer to turn his whims into policy — like, say, shutting down the government on the advice of Fox News hosts or pulling troops from Syria on the advice of a Turkish autocrat.

The biggest risk may be that an external emergency — a war, a terrorist attack, a financial crisis, an immense natural disaster — will arise. By then, it will be too late to pretend that he is anything other than manifestly unfit to lead.

For the country’s sake, there is only one acceptable outcome, just as there was after Americans realized in 1974 that a criminal was occupying the Oval Office. The president must go.

Achieving this outcome won’t be easy. It will require honorable people who have served in the Trump administration to share, publicly, what they have seen and what they believe. (At this point, anonymous leaks are not sufficient.) It will require congressional Republicans to acknowledge that they let a con man take over their party and then defended that con man. It will require Democrats and progressive activists to understand that a rushed impeachment may actually help Trump remain in office.

But if removing him will not be easy, it’s not as unlikely as it may sometimes seem. From the beginning, Trump has been an unusually weak president, as political scientists have pointed out. Although members of Congress have not done nearly enough to constrain him, no other recent president has faced nearly so much public criticism or private disdain from his own party.

Since the midterm election showed the political costs that Trump inflicts on Republicans, this criticism seems to be growing. They have broken with him on foreign policy (in Saudi Arabia, Yemen and Syria) and are anxious about the government shutdown. Trump is vulnerable to any erosion in his already weak approval rating, be it from an economic downturn, more Russia revelations or simply the defection of a few key allies. When support for an unpopular leader starts to crack, it can crumble.

Before we get to the how of Trump’s removal, though, I want to spend a little more time on the why — because even talking about the ouster of an elected president should happen only under extreme circumstances. Unfortunately, the country is now so polarized that such talk instead occurs with every president. Both George W. Bush and Barack Obama were subjected to reckless calls for their impeachment, from members of Congress no less.

So let’s be clear. Trump’s ideology is not an impeachable offense. However much you may disagree with Trump’s tax policy — and I disagree vehemently — it is not a reason to remove him from office. Nor are his efforts to cut government health insurance or to deport undocumented immigrants. Such issues, among others, are legitimate matters of democratic struggle, to be decided by elections, legislative debates, protests and the other normal tools of democracy. These issues are not the “treason, bribery or other high crimes and misdemeanors” that the founders intended impeachment to address.

Yet the founders also did not intend for the removal of a president to be impossible. They insisted on including an impeachment clause in the Constitution because they understood that an incompetent or corrupt person was nonetheless likely to attain high office every so often. And they understood how much harm such a person could do. The country needed a way to address what Alexander Hamilton called “the abuse or violation of some public trust” and James Madison called the “incapacity, negligence or perfidy” of a president.

The negligence and perfidy of President Trump — his high crimes and misdemeanors — can be separated into four categories. This list is conservative. It does not include the possibility that his campaign coordinated strategy with Russia, which remains uncertain. It also does not include his lazy approach to the job, like his refusal to read briefing books or the many empty hours on his schedule. It instead focuses on demonstrable ways that he has broken the law or violated his constitutional oath.

Trump has used the presidency for personal enrichment.

Regardless of party, Trump’s predecessors took elaborate steps to separate their personal financial interests from their governing responsibilities. They released their tax returns, so that any potential conflicts would be public. They placed their assets in a blind trust, to avoid knowing how their policies might affect their own investments.

Trump has instead treated the presidency as a branding opportunity. He has continued to own and promote the Trump Organization. He has spent more than 200 days at one of his properties and billed taxpayers for hundreds of thousands of dollars.

If this pattern were merely petty corruption, without damage to the national interest, it might not warrant removal from office. But Trump’s focus on personal profit certainly appears to be affecting policy. Most worrisome, foreign officials and others have realized they can curry favor with the president by spending money at one of his properties.

Saudi Arabia has showered the Trump Organization with business, and Trump has stood by the Saudis despite their brutal war in Yemen and their assassination of a prominent critic.

A Chinese government-owned company reportedly gave a $500 million loan to a Trump-backed project in Indonesia; two days later, Trump announced that he was lifting sanctions on another well-connected Chinese company.

These examples, and many more, flout Article 1 of the Constitution, which bans federal officeholders from accepting “emoluments” from any foreign country unless Congress approves the arrangement. Madison, when making the case for an impeachment clause, spoke of a president who “might betray his trust to foreign powers.”

Then, of course, there is Russia. Even before Robert Mueller, the special counsel, completes his investigation, the known facts are damning enough in at least one way. Trump lied to the American people during the 2016 campaign about business negotiations between his company and Vladimir Putin’s government. As president, Trump has taken steps — in Europe and Syria — that benefit Putin. To put it succinctly:

The president of the United States lied to the country about his commercial relationship with a hostile foreign government toward which he has a strangely accommodating policy.

Combine Trump’s actions with his tolerance for unethical cabinet officials — including ones who have made shady stock trades, accepted lavish perks or used government to promote their own companies or those of their friends — and the Trump administration is almost certainly the most corrupt in American history. It makes Warren G. Harding’s Teapot Dome scandal look like, well, a tempest in a teapot.

Trump has violated campaign finance law.

Federal prosecutors in New York filed papers last month alleging that Trump — identified as Individual-1 — directed a criminal plan to evade campaign finance laws. It happened during the final weeks of the 2016 campaign, when he instructed his lawyer, Michael Cohen, to pay a combined $280,000 in hush money to two women with whom Trump evidently had affairs. Trump and his campaign did not disclose these payments, as required by law. In the two years since, Trump has lied publicly about them — initially saying he did not know about the payments, only to change his story later.

It’s worth acknowledging that most campaign finance violations do not warrant removal from office. But these payments were not most campaign finance violations. They involved large, secret payoffs in the final weeks of a presidential campaign that, prosecutors said, “deceived the voting public.” The seriousness of the deception is presumably the reason that the prosecutors filed criminal charges against Cohen, rather than the more common penalty of civil fines for campaign finance violations.

What should happen to a president who won office with help from criminal behavior? The founders specifically considered this possibility during their debates at the Constitutional Convention. The most direct answer came from George Mason: A president who “practiced corruption and by that means procured his appointment in the first instance” should be subject to impeachment.

Trump has obstructed justice.

Whatever Mueller ultimately reveals about the relationship between the Trump campaign and Russia, Trump has obstructed justice to keep Mueller — and others — from getting to the truth.

Again and again, Trump has interfered with the investigation in ways that may violate the law and clearly do violate decades-old standards of presidential conduct. He

pressured James Comey, then the F.B.I. director, to let up on the Russia investigation, as a political favor. When Comey refused, Trump fired him. Trump also repeatedly

pressured Jeff Sessions, the attorney general, to halt the investigation and ultimately forced Sessions to resign for not doing so. Trump has also

publicly hounded several of the government’s top experts on Russian organized crime, including Andrew McCabe and Bruce Orr.

And Trump has repeatedly lied to the American people.

He has claimed, outrageously, that the Justice Department tells witnesses to lie in exchange for leniency. He has

rejected, with no factual basis, the findings of multiple intelligence agencies about Russia’s role in the 2016 campaign. He reportedly

helped his son Donald Trump Jr. draft a false statement about a 2016 meeting with a Russian lawyer.

Obstruction of justice is certainly grounds for the removal of a president. It was the subject of the first Nixon article of impeachment passed by the House Judiciary Committee. Among other things, that article accused him of making “false or misleading public statements for the purpose of deceiving the people of the United States.”

Trump has subverted democracy.

The Constitution that Trump swore to uphold revolves around checks and balances. It depends on the idea that the president is not a monarch. He is a citizen to whom, like all other citizens, the country’s laws apply. Trump rejects this principle. He has instead tried to undermine the credibility of any independent source of power or information that does not serve his interests.

It’s much more than just the Russia investigation. He has

tried to delegitimize federal judges based on their ethnicity or on the president who appointed them, drawing a rare rebuke from Chief Justice John Roberts. Trump has

criticized the Justice Department for indicting Republican politicians during an election year. He has

called for Comey, Hillary Clinton and other political opponents of his to be jailed. Trump has .

described journalists as “the enemy of the people” — an insult usually leveled by autocrats. He has

Individually, these sins may not seem to deserve removal from office. Collectively, though, they exact a terrible toll on American society. They cause people to lose the faith on which a democracy depends — faith in elections, in the justice system, in the basic notion of truth.

No other president since Nixon has engaged in behavior remotely like Trump’s. To accept it without sanction is ultimately to endorse it. Unpleasant though it is to remove a president, the costs and the risks of a continued Trump presidency are worse.

What now?

The most relevant precedent for the removal of Trump is Nixon, the only American president to be forced from office because of his conduct. And two aspects of Nixon’s departure tend to get overlooked today. One, he was never impeached. Two, most Republicans — both voters and elites — stuck by him until almost the very end. His approval rating among Republicans was still about 50 percent when, realizing in the summer of 1974 that he was doomed, he resigned.

The current political dynamics have some similarities. Whether the House of Representatives, under Democratic control, impeaches Trump is not the big question. The question is whether he loses the support of a meaningful slice of Republicans.

I know that many of Trump’s critics have given up hoping that he ever will. They assume that Republican senators will go on occasionally criticizing him without confronting him. But it is a mistake to give up. The stakes are too large — and the chances of success are too real.

Every one of these descriptions comes from a Republican member of Congress or of Trump’s own administration.

They know. They know he is unfit for office. They do not need to be persuaded of the truth. They need to be persuaded to act on it.

.. Democrats won’t persuade them by impeaching Trump. Doing so would probably rally the president’s supporters. It would shift the focus from Trump’s behavior toward a group of Democratic leaders whom Republicans are never going to like. A smarter approach is a series of sober-minded hearings to highlight Trump’s misconduct.

Democrats should focus on easily understandable issues most likely to bother Trump’s supporters, like corruption.

If this approach works at all — or if Mueller’s findings shift opinion, or if a separate problem arises, like the economy — Trump’s Republican allies will find themselves in a very difficult spot. At his current approval rating of about 40 percent, Republicans were thumped in the midterms. Were his rating to fall further, a significant number of congressional Republicans would be facing long re-election odds in 2020.

Two examples are Cory Gardner of Colorado and Susan Collins of Maine, senators who, not coincidentally, have shown tentative signs of breaking with Trump on the government shutdown. The recent criticism from Mitt Romney — who alternates between critical and sycophantic, depending on his own political interests — is another sign of Trump’s weakness.

For now, most Republicans worry that a full break with Trump will cause them to lose a primary, and it might. But sticking by him is no free lunch. Just ask the 27 Republican incumbents who were defeated last year and are now former members of Congress. By wide margins, suburban voters and younger voters find Trump abhorrent. The Republican Party needs to hold its own among these voters, starting in 2020.

It’s not only that Trump is unfit to be president and that Republicans know it. It also may be the case that they will soon have a political self-interest in abandoning him. If they did, the end could come swiftly. The House could then impeach Trump, knowing the Senate might act to convict. Or negotiations could begin over whether Trump deserves to trade resignation for some version of immunity.

Finally, there is the hope — naïve though it may seem — that some Republicans will choose to act on principle. There now exists a small club of former Trump administration officials who were widely respected before joining the administration and whom Trump has sullied, to greater or lesser degrees. It includes

Rex Tillerson,

Gary Cohn,

H.R. McMaster and

Jim Mattis.

Imagine if one of them gave a television interview and told the truth about Trump. Doing so would be a service to their country at a time of national need. It would be an illustration of duty.

Throughout his career, Trump has worked hard to invent his own reality, and largely succeeded. It has made him very rich and, against all odds, elected him president. But whatever happens in 2019, his false version of reality will not survive history, just as Nixon’s did not. Which side of that history do today’s Republicans want to be on?

The conservative case for a Republican Senate and a Democratic House.

.. Let me suggest a third option. If you are a conservative who is moderately happy with some of Trump’s policy steps, fearful of liberalism in full power, but also fearful of Trump untrammeled and triumphant, the sensible thing to root for — and vote for — is the outcome that appears most likely at the moment: A Republican majority in the Senate and a Democratic majority in the House of Representatives.

.. The best argument for conservative support for Donald Trump was always defensive: Elect him and you prevent the installation of a long-term liberal majority on the Supreme Court, and perhaps chasten the Democratic Party and arrest its leftward march.

For that argument to persuade, you had to trust the institutional Republican Party’s promise to contain Trump’s authoritarian instincts and restrain his follies. You also had to downplay the long-term damage, to conservatism and the body politic, of putting someone with such poisonous rhetorical habits in the bully pulpit.

.. so far Trump has been more constrained and less destructive than I expected — his foreign policy less destabilizing (so far) than either of his predecessors, his cruelest policy instincts walked back under pressure, the country more prosperous, his appointments more responsible and a large-scale investigation into his possible crimes proceeding, beset by Trumpian insults but otherwise mostly unimpeded by the White House.

To the extent that any Republicans deserve credit for this constraint, though, they are mostly elected Republicans in the Senate. The House is more pure, uncut MAGA, more reflexive in its defense of a president whose behavior is often indefensible, more poisoned by the worst Trumpist tendencies (witness the steady migration of the Iowa congressman Steve King toward an overt white nationalism) and more inclined to allow Trump a free hand should he seek to make his actual presidency exactly like his Twitter feed.

.. So a Democratic House would supply a much more effective check on that temptation, along with more vigorous scrutiny of corruption in the White House, about which congressional Republicans have been studiously incurious. And it would offer that check without jeopardizing any potential conservative legislative achievements — because, let’s be frank, the congressional G.O.P. isn’t going to do anything serious with its power if it gets re-elected except confirm judges, and you don’t need the House to elevate Amy Coney Barrett if there’s one more high court vacancy.

.. for the genuinely populist sort for conservative (that is, the best kind), having a Democratic House might force Trump himself back toward the economic populism of his campaign, which he mostly abandoned but has suddenly remembered in the last days before the midterms, talking up a phantom middle-class tax cut and proposing an “America First” approach to drug pricing.

.. So giving up the House restrains and redirects Trump at relatively little cost, and perhaps even some policy advantage. Keeping the Senate Republican in this cycle, on the other hand, doesn’t just allow for more conservative judicial nominations. It also provides a hedge against a future where the Democratic Party returns to power flush with ideological zeal, committed to its own forms of norm-busting, and eager for a measure of revenge.

Given the more favorable Senate map and the possibility of a recession, Democrats can reasonably hope to retake the upper chamber in the next four years no matter what. And it will go much worse for the right if that Democratic majority has 60 seats in that scenario as opposed to 52 — something that will be determined by this fall’s election as much as by what happens two or four years hence.

Of course, if you’re a Trump skeptic who believes that only an earth-salting defeat will enable the re-emergence of a decent right, then trying to constrain a future liberalism will seem less important than rooting for the necessary disaster to arrive for Republicans today. But I don’t think our polarized system lends itself to salt-the-earth defeats anymore, and I also don’t think that parties necessarily emerge from them wiser than before — since in such defeats they’re condensed to their more fervent and often foolish core.

After President Trump’s Terrible Tuesday, Republican lawmakers need to stop pretending that there are any red lines that he won’t cross.

Congressional Republicans have been operating under a see-no-evil policy with President Trump: ignoring his lying, his subversions of democratic norms and his attacks on government institutions or, when that’s not possible, dismissing such outrages as empty bluster — as Trump being Trump.

..Also on Tuesday, a federal jury convicted Mr. Trump’s former campaign chairman, Paul Manafort, of bank and tax fraud. How did Mr. Trump react? More like a Mafia don than a guardian of the rule of law. While criticizing Mr. Cohen on Wednesday, the president tweeted that, by contrast, he had “such respect for a brave man” like Mr. Manafort, who “refused to ‘break’ … to get a ‘deal.’ ” The president, in other words, felt moved to praise a convicted felon for refusing to cooperate in the pursuit of justice.

.. And how did Republicans in Congress react? They didn’t, if they could avoid it. John Cornyn, the majority whip in the Senate, shrugged that he had “no idea about what the facts” of Mr. Cohen’s guilty plea were “other than the fact that none of it has anything to do with the Russia investigation.” The office of the House speaker, Paul Ryan, said it needed “more information.” Most members opted for silence.

.. When members of Mr. Trump’s party pooh-pooh his thuggish rantings and otherwise signal that they will overlook even his most dangerous behavior, they are inviting him to act out even more. Like a willful toddler, Mr. Trump lives to test limits.

.. Republican lawmakers need not attack Mr. Trump in order to stop enabling his worst impulses and begin distancing themselves from his corruption. They simply need to stop cowering. An obvious first step is for Congress to pass legislation protecting Robert Mueller’s Russia inquiry

.. The president has toyed with the idea of firing Mr. Muellerand his superior, Deputy Attorney General Rod Rosenstein, moves that would ignite a constitutional crisis. Lawmakers are deluding themselves to think that he won’t consider such radical acts again as his predicament grows more dire.

.. Much of the groundwork for a bill to protect the Russia investigation has already been laid, with a bipartisan plan having passed the Senate Judiciary Committee. Shamefully, Senator Mitch McConnell, the Republican majority leader, has refused to bring the bill up for a vote

.. insisting that it is unnecessary because of course the president would never fire Mr. Mueller.

.. Mr. Ryan has spouted similar assurances. Then again, Mr. Ryan also laughed off the idea that Mr. Trump would strip his political critics of their security clearances, so clearly Republican leaders are not the best barometers of this president’s thinking.

.. Speaking of Mr. Ryan, the speaker needs to shut down the attacks on Mr. Rosenstein by Mr. Trump’s lackeys in the arch-conservative Freedom Caucus.

.. Mark Meadows and Jim Jordan threatened to force an impeachment vote on Mr. Rosenstein, claiming that he was impeding Congress’s harassment — uh, “investigation” — of the Justice Department and the F.B.I. When that plan flopped, the men set their sights on holding Mr. Rosenstein in contempt of Congress — which doesn’t sound as dramatic, but would, if successful, provide Mr. Trump an excuse to oust Mr. Rosenstein and replace him with a lap dog.

.. Once upon a time, campaign finance violations made congressional Republicans very angry indeed. During Bill Clinton’s second term, there was quite an uproar over allegations that the Chinese government had attempted to influence the 1996 presidential race via illegal campaign contributions. (Does Vice President Al Gore’s visit to a certain Buddhist temple ring any bells?)

.. His efforts to hide the money trail suggest he knew his behavior wasn’t kosher. And while the initial payments to the women were made before Mr. Trump won the election, he didn’t begin compensating Mr. Cohen until February of 2017 — thus any conspiracy was carried straight into the Oval Office.

.. Every week seems to bring fresh evidence that Mr. Trump, his inner circle and his main backers do not consider themselves bound by such pedestrian concepts as truth, ethics or the law. The latest confirmation for that was the corruption indictment of Representative Duncan Hunter, Mr. Trump’s second campaign supporter in the House. The first, Representative Chris Collins, was indicted two weeks ago on insider-trading charges.

Congress, unfortunately, remains crouched and trembling in a dark corner, hoping this is all a bad dream. It’s not. Republican lawmakers need to buck up, remind themselves of their constitutional responsibilities and erect some basic guardrails to ensure that — in a fit of rage, panic or mere pique — this president does not wake up one morning and decide to drive American democracy off a cliff.

How much power will a president with such tenuous claim to it get to wield? How profound and durable an impact will such a shallow and fickle person make?

.. Donald Trump barely won the White House, under circumstances — a tainted opponent, three million fewer votes than she received, James Comey’s moral vanity and Russia’s amoral exertions — that raise serious questions about how many Americans yearned to see him there.

.. In his heart of hearts, he doesn’t give a damn about rolling back abortion rights. Any sane analysis of his background and sober read of his character leads to that conclusion. Yet this man of all men — a misogynist, a philanderer, a grabber-by-the-you-know-what — may be the end of Roe v. Wade.

.. So many of Trump’s positions, not just on abortion but also on a whole lot else, were embraced late in the game, as matters of political convenience. They were his clearest path to power. Then they were his crudest way to flex it.

.. Now they’re his crassest way to hold on to it. He will almost certainly move to replace Kennedy with a deeply, unswervingly conservative jurist not because that’s consistent with his own core (what core?) but because it’s catnip to the elements of his base that got him this far and could carry him farther.

.. Never mind how much it exacerbates this country’s already crippling political polarization

.. his is a moment, if ever there was one, to set a bipartisan example and apply a healing touch.

.. Trump will gladly cleave the country in two before he’ll dim the applause of his most ardent acolytes.

.. He will bully, both ideologically and tactically. And he will get his way, because — this is part of that cosmic joke — the advantages seem always to cut his way. The obstacles teeter and collapse.

.. Other presidents have had to worry about getting 60 votes in the Senate for Supreme Court nominations to proceed. Not Trump.

.. McConnell used the “nuclear option” once already, for Neil Gorsuch, rendering a Democratic filibuster irrelevant. So the precedent has been set.

.. In fact three of them — Joe Manchin of West Virginia, Joe Donnelly of Indiana and Heidi Heitkamp of North Dakota — supported Gorsuch’s confirmation last year. It’s no accident that North Dakota, which Trump won by nearly 36 points, was the site of his rally on Wednesday night.

.. his sneering, gloating, uncompromising response to that aren’t a familiar combination.

.. It’s impossible to square the roughly 77,000 votes by which he won the Electoral College with the license that he has given himself and the rein that the members of his adopted party have given him.

.. the truth about Trump is the opposite of the story he tells. He points to Robert Mueller’s investigation and to negative media coverage and portrays himself as a modern-day martyr.

.. But he’s the luckiest man alive. Although he savaged the G.O.P. en route to its presidential nomination, he was greeted in Washington by a mum McConnell, a blushing Paul Ryan and a mostly obsequious Republican congressional majority.

.. with a handpicked replacement for Kennedy, he’d probably have “fewer checks on his power than any president in his lifetime

.. “The media, normally the last check on a president with total control of government, has lost the trust of most Republicans and many Democrats, after two years of Trump pummeling.”

.. That doesn’t account for a Democratic takeover of at least one chamber of Congress, the importance of which cannot be overstated.

.. conscience. A better man might shudder somewhat at the division that he was sowing and the wreckage in his wake. Trump merely revels in his ability to pull off what nobody thought he could. Shamelessness is his greatest gift. How unfunny is that?